Ch.10

Origin: Maxilla and mandible Insertion: into muscle and skin at angles of mouth Action: closes lips

Orbicularis Oris

Origin: zygomatic bone Insertion: skin and muscle at corner of mouth Action: raises corners of mouth

Zygomaticus

Origin: mandible below incisors Insertion: Skin of chin Action: wrinkles chin, protrudes lower lip (as in a pout)

Mentalis

Origin: fascia of chest Insertion: lower margin of mandible Action: Tenses skin of neck, pulls lower lip back and down (downward sag of mouth)

Platysma

origin: arch of frontal bone above nasal bone insertion: skin of eyebrow action: pulls eyebrows medially and inferiorly, wrinkles skin of forhead

Corrugator supercilii

Origin: Frontal and maxillary bones Insertion: Tissue of eyelids Action: Closes eye, pulls eyebrow inferiorly

Orbicularis Oculi

Two part muscle consisting of the frontal and occipital bellies connected by epicranial aponeurosis. The alternate actions pulls scalp forward and backward

Epicranius (Occipitofrontalis)

Origin: epicranial aponeurosis Insertion: skin of eyebrows and root of nose Action: raises eyebrows and wrinkles forhead skin horizontally

Frontal belly

Origin: occipital bone and temporal bones Insertion: epicranial aponeurosis Action: Pulls scalp posteriorly

Occipital Belly

Origin: fascia associated with masseter muscle Insertion: skin at angle of mouth Action: pulls corner of lip laterally, tenses lip; synergist of zygomatic

Risorius

Origin: Zygomatic arch and bone Insertion: angle and ramus of mandible Action: Prime mover of jaw; closure

Masseter (1/3 chewing muscles)

Origin: Molar region of maxilla and mandible Insertion: corner of the mouth (orbicularis oris) Action: compress cheeks

Buccinator

Origin: temporal fossa Insertion: coronoid process of mandible action: closes jaw

Temporalis (1/3 chewing muscles)

Origin: Pterygoid plate of sphenoid bone Insertion: Medial surface of mandible near the angle Action: Acts with the lateral pterygoid muscle to protract (pull anteriorly) the mandible and promote side-to-side grinding movement

Medial Pterygoid (1/3 chewing muscles)

Origin: greater wing and lateral pterygoid plate of sphenoid bone Insertion: Condylar process of mandible Action: Provides side-to-side grinding movements

Lateral Pterygoid (1/3 chewing muscles)

Origin: transverse process of C1-C4 Insertion: Medial border of scapula, superior to spine Action: elevates and adducts scapula

Levator Scapulae

Origin: Manubrium of sternum Insertion: mastoid process of temporal bone Action: Flexes and laterally rotates the head

Sternocleidomastoid

Origin: transverse processes of cervical vertebrae Insertion: anterolaterally on first two ribs Action: Elevate first two ribs

Scalenes

Origin: inferior border of rib above Insertion: superior border of rib below Action: Pull ribs toward one another to elevate rib cage

external intercostals

Origin: Superior border of rib below Insertion: Inferior border of rib above Action: Pull ribs together and depress rib

internal intercostals

Origin: Inferior, internal surface of rib cage and sternum, costal cartilages Insertion: Central tendon Action: Prime mover of inspiration; flattens on contraction

Diaphragm

Origin: pubic crest and symphysis Insertion: xiphoid process and costal cartilages of ribs 5-7 Action: flexes and rotates lumbar region of vertebral column

Rectus Abdominis

Origin: fleshy strips from outer surfaces of lower eight ribs Insertion: fibers insert into linea alba via a broad aponeurosis; some insert into pubic crest Action: flex vertebral column and compress abdominal wall and trunk rotation and lateral flexion

External Oblique

Origin: lumbar fascia, iliac crest, inguinal ligament Insertion: linea alba Action: as for external oblique

Internal Oblique

Origin: inguinal ligament, lumbar fascia Insertion: linea alba, pubic crest Action: compresses abdominal contents

Transversus Abdominis

Origin: ribs 3-5 insertion: coracoid process of scapula Action: with ribs fixed, pulls scapula forward and downward

Pectoralis Minor

origin: ribs 1-8 insertion: entire anterior surface of medial border of scapula Action: Rotates scapula so its inferior angle moves laterally and upward

Serratus Anterior

Origin: ligamentum nuchae Insertion: continuous insertion along acromion and spin of scapula Action: Retracts, and rotates scapula

Trapezius

Origin: spinous processes of C7-T1 (minor), spinous processes of T2-T5 (major) Insertion: medial border of scapula Action: stabilize scapula

Rhomboid Major and Minor

Origin: Sternal End of Clavicle Insertion: Fibers converge to insert by a short tendon Action: Adducts medially rotates arm

pectoralis major

Origin: Lateral third of clavicle Insertion: Deltoid tuberosity of humerus Action: Prime mover of the arm when all its fibers contract simultaneously

Deltoid

Origin: indirect attachment via lumbodorsal fascia into spines Insertion: Spirals around teres major Action: Prime mover of arm extention; powerful arm addcutor; medially rotates arm

Latissimus Dorsi

Origin: subscapular fossa Insertion: lesser tubercle of humerus Action: Rotates arm medially

Subscapularis

Origin: supraspinous fossa of scpula Insertion: superior part of greater tubercle of humerus Action: Intiates abduction of arm

Supraspinatus

Origin: Infraspinous fossa of scapula Insertion: Greater tubercle of humerus posterior to insertion Action: Rotates arm laterally

Infraspinatus

Origin: Lateral border of dorsal scapular surface Insertion: Greater tubercle of humerus inferior to infraspinatus insertion Action: Same as infraspinatus

Teres Minor

Origin: Posterior surface of scapula Insertion: Crest of lesser tubercle Action: Extends, medially rotates, and adducts arm

Teres Major

Origin: coracoid process of scapula Insertion: medial surface of humerus shaft Action: Flexes and adducts arm

Coracobrachialis

Origin: Long head infraglenoid tubercle Insertion: common tendon into olecranon on ulna Action: Powerful forearm extensor

Triceps Brachii

Origin: Short head: coracoid Insertion: common tendon into radial tuberosity Action: Flexes and supinates forearm

Biceps Brachii

Origin: Anterior side of humerus Insertion: Tuberosity and coronoid process Action: Flexes forearm

Brachialis

Origin: Lateral supracondylar ridge at distal end of humerus Insertion: Base of radial styloid process Action: Synergist in flexing forearm

Brachioradialis

Origin: Medial epicondyle Insertion: common tendon into lateral radius Action: Pronates forearm

pronator teres

Origin: Medial epicondyle of humerus Insertion: Base of second and third metacarpals Action: Powerful Flexor of hand

flexor carpi radialis

Origin: Medial epicondyle Insertion: Fascia of palm Action: Tenses skin and fascia of palm during movements

Palmaris Longus

Origin: Medial epicondyle of humerus Insertion: Pisiform and hamate bones Action: Powerful flexor and adductor of hand

Flexor Carpi Ulnaris

Origin: Medial epicondyle of humerus Insertion: four tendons into middle phalanges Action: Flexes hand and middle phalanges of second to fifth fingers

flexor digitorum superficialis

Origin: coronoid process Insertion: four tendons into distal phalanges Action: Flexes distal interphalangeal joints

flexor digitorum profundus

Origin: lateral supracondylar ridge of humerus Insertion: Base of second metacarpal Action: Extends hand and abducts hand

Extensor Carpi Radialis Lonhgus

Origin: Lateral epicondyle of humerus Insertion: Base of third metacarpal Action: Extends and abducts hand

Extensor Carpi Radialis Brevis

Origin: Lateral epicondyle of humerus Insertion: Four tendons into extensor expansions Action: Prime mover of finger extention

Extensor Digitorum

Origin: Lateral epicondyle of humerus Insertion: Base of fifth metacarpal Action: Extends hand, abducts hand

Extensor Carpi Ulnaris

Origin: Lateral epicondyle of humerus Insertion: Proximal end of radius Action: assists biceps brachii to forcibly supinate forearm

Supinator

Origin: posterior surface of radius and ulna Insertion: Base of first metacarpal and trapezium Action: Abducts and extends thumb

Abductor Pollicis Longus

Origin: Dorsal shaft of radius Insertion: Base of proximal and distal phalanx of thumb Action: Extends thumb

extensor pollicis brevis and longus

made up of the iliacus and psoas major

Illiopsoas

Origin: iliac fossa Insertion: Lesser trochanter of femur Action: Prime mover for flexing thigh

Iliacus

Origin: Fleshy slips from transverse process Insertion: Lesser trochanter of femur Action: prime mover of thigh and flexes vertebral column laterally

Psoas Major

Origin: Anterior superior iliac spine Insertion: medial proximal tibia Action: Flexes, abducts and laterally rotates thigh

Sartorius

Origin: pubis Insertion: lesser trochanter inferior to linea aspera Action: Adducts, flexes and medially rotates thigh

Pectineus

Origin: Pubis near pubic symphysis Insertion: linea aspera Action: Adducts, flexes and medially rotates thigh

adductor longus

Origin: ischial and pubic rami Insertion: linea aspera and adductor Action: adducts and medially rotates and flexes thigh

Adductor Magnus

Origin: inferior ramus and body of pubis Insertion: medial surface of tibia Action: adducts thigh, flexes and medially rotates leg

Gracillis

Origin: anterior inferior iliac spine and acetabulum Insertion: patella and tibial tuberosity Action: Extends leg and flexes thigh at hip

Rectus Femoris

Origin: Greater Trochanter, intertrochanteric line, gluteal tuberosity, linea aspera Insertion: Patella, Tibial tuberosity, lateral+medial condyles Action: Extends leg and stabilizes knee

Vastus Lateralis

Origin: Intertrochanteric line, linea aspera, medial supracondylar line Insertion: Patella, Tibial tuberosity, lateral+medial condyles Action: Extends legs

Vastus medialis

Origin: Anterior and lateral surfaces of femur Insertion: Patella, Tibial tuberosity, lateral+medial condyles Action: Extends leg

vastus intermedius

Origin: Anterior aspect of iliac crest Insertion: iliotibial tract Action: Steadies the leg and trunk on thigh by tightening iliotibial tract

Tensor Fascia Lata

Origin: Dorsal ilium, sacrum and coccyx Insertion: gluteal tuberosity Action: Major extensor of thigh

Gluteus Maximus

Origin: Between anterior and posterior gluteal lines Insertion: Short tendon into lateral aspect Action: Abducts and medially rotates thigh

Gluteus Medius

Origin: Anterolateral surface Insertion: superior border of greater trochanter Action: Rotates extended thigh laterally

Piriformis

Origin: Ischial tuberosity Insertion: head of fibula and lateral condyle of tibia Action: Extends thigh and flexes leg

Biceps femoris

Origin: Ischial tuberosity Insertion: Medial aspect of upper tibial shaft Action: Extends thigh and flexes leg

Semitendinosus

Origin: ischial tuberosity Insertion: Medial condyle of tibia Action: Extends thigh and flexes leg

Semimembranosus

Origin: Lateral condyle Insertion: medial cuneiform and first metatarsal Action: Prime mover of dorsiflexion

tibialis anterior

Origin: Lateral condyle of tibia Insertion: Middle and distal phalanges Action: Prime mover of toe extension

extensor digitorum longus

Origin: Anteromedial fibula Insertion: distal phalanx of great toe Action: Extends great toe

Extensor Hallucis Longus

Origin: head and upper portion Insertion: first metatarsal and medial cuneiform Action: plantar flexes and everts foot

Fibularis longus

Origin: Distal fibula shaft Insertion: lateral malleolus Action: Plantar flexes everts foot

fibularis brevis

Origin: medial and lateral condyles of femur Insertion: Posterior clacaneus Action: plantar flexes foot

Gastrocnemius

Origin: Extensive origin from superior tibia Insertion: gastrocnemius Action: plantar flexes foot

Soleus

Origin: lateral condyle of femur Insertion: proximal tibia Action: Flexes, rotates leg medially to unlock extended knee when flexion begins

Popliteus

Origin: superior tibia and fibula Insertion: medial malleolus and under arch of foot Action: Prime mover of foot inversion

Tibialis Posterior

Origin: Posterior tibia Insertion: medial malleolus and distal phalanges of second-fifth toes Action: plantar flexes and inverts foot

Flexor Digitorum Longus

Origin: Midshaft of fibula Insertion: distal phalanx Action: plantar flexes and inverts foot; flexes great toe

Flexor Hallucis Longus